Design of Electric Motors, Generators, and Drive Systems

The melding of advanced embedded control, power electronics, and electric machines has created a new workhorse for industrial and consumer electromechanical energy conversion systems. Electrification will reduce the carbon dioxide output of our economy. Electric motors will replace many other sources of motive power for many industrial purposes. Actively-controlled electric machines are already bringing new profiles for position, speed, and force control, creating consumer products that were previously inconceivable at practical prices.

Electric actuators are increasingly found in just about everything used for daily life, from automobiles to kitchen appliances to smart devices. Modern product design and industrial fabrication demand an understanding of electric machine characteristics, modern control techniques, and associated interactions with electronic drives. Computer-based tools for estimating machine parameters and performance can remarkably speed up a designer's understanding of when different control and machine design assumptions are applicable, and how gracefully these assumptions fail as performance limits are approached. Combinations of motors (electromechanics) and drives (power electronics) can synergistically achieve performance not possible through other means.

This course focuses on the analysis and design of electric motors, generators, and associated power electronic drive systems, placing special emphasis on the design of machines for electric drives, including traction drives, drive motors for automated manufacturing (robots), material handling and drive motors for automotive, aircraft and marine propulsion systems, and associated power electronic drives. Participants will gain extensive hands-on experience by participating in computer-based laboratory exercises in a MATLAB-compatible, open-source scientific analysis tool called Octave. Participants will also engage in a hardware build session using an Infineon “Programmable System on Chip” (PSoC) 5LP to control a machine in our instructional laboratories. The PSoC 5LP is one of a family of processors that can provide sophisticated calculation, reconfigurable hardware, and IoT communication in different applications.

Course exercises will additionally investigate machine performance as affected by design measures such as selection of pole and slot count, winding details, induction machine slot profiles, and optimization of magnets. Computer-based simulation tools will be used to discuss control strategies for different machine types and address optimization techniques, including matching motor design to performance requirements.

Throughout the course, participants will assess performance considerations, trade-offs, and design approaches and access computer facilities and analysis routines for practice in machine analysis and design. Hardware experience will include building and programming a small, motor drive using a processor from a family of IoT-capable programmable controllers.

COVID-19 Updates

We fully expect to resume on-campus Short Programs courses during the Summer of 2022. However, the possibility remains of ongoing disruption and restrictions due to COVID-19 which may require that the course be delivered via live virtual format. Please read more here.

• Understand the field and energy conservation description of magnetic forces
• Use circuit techniques to describe electric machinery
• Describe power electronic circuits used to control electric machines
• Explore power electronic losses and efficiency as affected by frequency of operation.
• Assess the expansion of windings in space harmonics and use of those space harmonics to describe machine operation
• Discover how permanent magnets are used in electric machinery
• Examine the interactions between electromechanics of motors and power electronics and controls
• Learn to apply operational requirements in electric machine design
• Receive an introduction to Programmable System-on-Chip (PSoC) embedded control

Program Outline

This course runs 9:30 am – 5:00 pm on Monday, and 8:30 am - 5:00 pm Tuesday through Friday.

As this courses focuses on magnetoquasistatic fundamentals of electric machinery and drives, one of the fundamental objectives is to gain (or to regain) an understanding of how Maxwell’s equations describe the relationship of electromagnetic fields with the internals of electric machinery, and how the fundamentals of electromagnetics describe how machines work. Power electronic circuits and their relationship with electric motors and generators will be discussed in depth. The staff of this subject have experience in design and evaluation of electric machinery and power electronic drives. That practical experience can be essential to machine designers. We expect to convey elements of that experience, such as how winding details impact machine efficiency, how multi-attribute optimization techniques can be used to evaluate alternative machine designs, how drive schemes in power electronics impact machine performance, how to incorporate performance requirements and how to formulate an optimal design routine.

Topics covered include:

• Elements of energy conversion: energy, co-energy, force and torque as derivatives of energy, field- based force calculations
• Energy conversion in electric machines: force and shear density, machine power density and efficiency
• Review of the principles of the basic machine types: synchronous, induction, variable reluctance
• Power electronic circuits including inverters, phase control and pulse width modulation
• Introduction to and exercises in the use of MATLAB and Octave
• Induction machines in some depth: reduction to an equivalent circuit and calculation of the elements of the circuit
• Performance evaluation of electric machines
• Field-oriented control
• Permanent magnet machines: review of basics, principals of energy conversion and design fundamentals
• Control strategies for PM machines: torque/speed limitations, taking advantage of negative saliency, elements of field oriented control
• Optimal machine design, considering application details
• Digitally-enabled embedded control applications

Links & Resources

Audio/Video:

• ILP VIDEO SERIES: Electric Motors Find New Roles in Robots, Ships, Cars, and Microgrids. MIT ILP Institute Insider, October 2016.

News/Articles:

• Electric Motors Find New Roles in Robots, Ships, Cars, and Microgrids. MIT ILP Institute Insider, October 2016.

This course is appropriate for:

• Engineers who want to improve the design or application of electric motors for industrial or traction drives
• Engineers who use electric machines for electric power generation and need to better understand their operation
• Engineering managers who want to improve their ability to oversee teams that work with electric motors

Relevant industries include land, sea, and air transportation; resource extraction; chemicals; manufacturing; and energy. Past attendees have included personnel from Apple, General Electric, BAE systems, Bose Corporation, General Dynamics, the U.S. Navy, MIT Lincoln Laboratory, Draper Laboratory, Northrop Grumman, Boeing, iRobot, Lockheed Martin, Baldor, Google, Pfizer, Nikon, the U.S. Army, and a host of universities.

Requirements

Participants should have at least a basic knowledge of electric circuit analysis and vector calculus and a working familiarity with the principles of electromagnetism.

A computer with internet access and MATLAB OR Octave is required. Octave is a free, open source program. Download and installation instructions will be provided prior to the course, if needed.

For the 2023 live virtual cohort, participants will receive a hardware microcontroller kit, which will be used during the course to construct a small motor drive. Enrolled registrants can keep the kit when the course is complete.